In vehicles using small engines, such as snowmobiles, the problem of a cold start still persists. Manual priming has been used but this usually involves direct access to the carburetor and engine.
The present invention contemplates a system to aid the starting of a cold engine which can be controlled from the cockpit of a vehicle.
Crankcase pulse pressure in internal combustion engines has been used in connection with carburetor systems. In a United States patent to Tuckey and Schneider, U.S. Pat. No. 3,633,557, a crankcase pulse controlled by a valve in a throttle shaft is directed to an idle system to give an acceleration charge when the throttle is open.
In a United States patent to Tuckey, U.S. Pat. No. 3,738,622, a crankcase pulse is used to actuate a fuel pump and a vapor pump. In U.S. Pat. No. 3,743,254 to Tuckey, a crankcase pulse is used to pulse a special spring backed diaphragm on the dry side to deliver an acceleration charge of fuel to a main jet in the carburetor. In U.S. Pat. No. 4,104,994 to Phillips, a throttle controlled crankcase pulse is used to aspirate fuel out of the main jet to the mixing passage of the carburetor.
Thus, crankcase pulse has been utilized in the control of fuel flow from a carburetor in various applications. According to the present invention, a crankcase pulse line is carried from the engine crankcase to the cowl of a vehicle or some other readily accessible place. A valve for manual control is placed in this line which is then carried to a carburetor fuel well or diaphragm. Particular manipulation of this valve can provide suitable conditions for starting and engine operation.
Other objects and features of the invention will be apparent in the following description and claims in which the principles of the invention are set forth together with a description of the invention and a disclosure directed to persons skilled in the art to enable the use of the invention.